Counter current extraction centrifuge



Jam 5, 1954 P. sTElNAcKER ETAL COUNTERCURRENT ExTRAcTIoN CENTRIFUGE 4 sheets-shew 1 Filed NOV. 19, 1949 INVEIITU RS Vl M E K@ W MVN. M O A EDM r ST Rw Mfr U, VHA.

Jan- 5, 1954 P. sTElNAcKER ETAL 2,665,061

COUNTERCURRENT EXTRACTION CEINTRFUGE Filed Nov. 19, 1949 '4 sheets-sheet 2 AUGUST BYNG PETER sTEmArfKFR v ATTO/e /y r Jan 5, 1954 P. STEINACKER ETAL COUNTERCURRENT EXTRACTION CENTRIFUGE 4.- SheelLS-Sheei'. 5

Filed Nov. 19, 1949 PET SHG. V.\ WCM.. .,/l NA. .o Emw VET A N T S n@ KG EU Jan. 5, 1954 P. STEINACKER ET RCURRENT EXTRACTION CENTRIFUGE Filed NOV. 19, 1949 wwwwwwwwwww,

INVENTGRS PETER STEIN/mw@ AUQUST 56mg dwooM/f ATTN/15a? lighter liquid being sealed against the stationary feeding channel for the specifically lighter liquid it is possible to feed this liquid to the centrifugal drum under overpressure. In this case there is no more a level of the specifically lighter liquid in the inlet chamber. The radius RL becomes equal to zero, and to the centrifugal pressure of the liquid column the over pressure p is added by means of which the specifically lighter liquid is led into the drum, so that the formula for determining the diameter of the discharging devices for the specifically lighter liquid reads as follows:

The drawings show preferred embodiments of the invention.

Fig. 1 is a vertical section through the centrifugal drum of a countercurrent extraction centrifugal machine with an inserted plate package, and with the discharging devices with overfiow edges for discharging the liquids,

Fig. 2 is a vertical section through a drum of similar structure, with stripping disks and a sealed connection between the inlet chamber for the specifically lighter liquid and the feeding channel for same,

Fig. 3 is a vertical section through a drum of similar structure, but with bent plates,

Fig. 4 is a vertical section through the drum of a, countercurrent extraction centrifugal machine with an inserted package of plates divided in three parts, and

Fig. 5 is an enlarged fragmentary view of a portion of the intermediate set of plates as shown in Fig. 4.

In Figs. 1 and 2 the filling of the drum of the specifically lighter liquid is indicated by horizontal dotted lines, and the drum filling for the specifically heavier liquid by vertical dotted lines. The direction of flow of the liquids is indicated by arrows.

In Fig. l the centrifugal drum with its inner portion 3 is screwed on the driving spindle by a nut 2. The cover 4 of the drum is connected with the outer bottom portion 3a of the drum by means of a threaded ring 5. The plate package 8 is borne by a hollow conical member 9 inserted into the drum the lower wall of this member 9 acting as a distributor for the specifically lighter liquid and the upper part 9a of said member surrounding the inlet chamber I for the specifically lighter liquid. The inserted member 9 is provided with ducts II lying in a distance :R from the axis of rotation of the drum, the ducts II leading to corresponding distributing channels I2 near the outer rims of the plates through which channels I2 the specifically lighter liquid enters into the plate package.

The specifically lighter liquid enters from the outside through the inlet pipe I3 into the inlet chamber I Il, and the specifically heavier liquid enters through the feed pipe I4 into an inlet chamber I which is formed by a combined separating disc I6, ISa. The latter has in its lower portion ducts I1 leading to corresponding channels IB of the plates 8 near their inner rims and forming a passage for the specifically heavier liquid to enter into the plate package.

The specifically heavier liquid fiows along the inner side of the plates 8 towards the outside into the space I9 defined by the outer shell 3a of the drum whence the liquid passes through channels 20 into the discharging chamber 2I situated between the drum cover 4 and the separating disk I6. The specifically heavier liquid leaves the drum from the chamber 2I over the inner or overflow edge of the disk 6. This overflow edge is positioned in a distance :RH from the axis of rotation of the drum. The revolving speed of the specifically heavier liquid on this spot is :v

Ig countercurrent to the specifically heavier liquid the specically lighter liquid flows along the outside of the plates 8 to the inside into the chamber 22 enclosed by the inner rims of the plates 8, and passes through channels 23 into the discharge chamber 24 whence it escapes out of the drum over the overflow edge of the separating disk I6.

The liquid level of the specifically lighter liquid in the inlet chamber I 0 lies in a distance :RL from the axis of rotation. The revolving speed of the specifically lighter liquid on this spot 1S :'DL.

The overflow edge of the disk 6 is situated in such a distance :RH from the axis of rotation of the drum, that the centrifugal pressure of the specifically heavier liquid from its level in the discharging chamber 2I up to the distributing channels I2 of the plates 8 near their outer rims, in the distance :R from the axis of rotation, is smaller than the centrifugal pressure of the specifically lighter liquid from its level in the inlet chamber IIl up to the distributing channels I4 near the outer rims of the plates 8, in the disstance :R from the axis of rotation.

In the distributing channels I2 and I8 both liquids are mixed. In the middle part of the plate package, between the inner and the outer distributing channels I8 and I2 respectively, the liquids fiow in counter current to each other and are still partially mixed with each other, while in the inner and outer parts of the plate package 8 a sharp separation of the liquids takes place.

Instead of discharging the liquids from the drum over the overflow edges of the disks 6 and IE the discharge may also be executed by means of stripping disks the diameter of which is designated according to the above mentioned formulae.

As shown in Fig. 2 the connection of the stationary feeding pipe 26 with the inner part 25 of the distributor 21 surrounding the inlet cham ber 28 for the specifically lighter liquid is executed by means of a gasket 29. The specifically lighter liquid is fed to the centrifugal drum under the overpressure p. The gasket 29 is fixed in a known manner between the inner rim of the distributor 25 and the threaded ring 30 and is pressed against the inlet pipe 26 by the overpressure of the liquid in the inlet chamber 28. The inlet chamber 28' is completely filled with the specifically lighter liquid, so that owing to this fact there is not even a free liquid level, but the over pressure p is already prevailing in the axis of rotation. The specifically lighter liquid flows through the distributing channels 3I lying in a distance :R from the axis of rotation, and enters the plate package 32. Thence the liquid flows along the outer sides of the plates into the chamber 33 between the inner rims of the plates and the upper portion 25 of the distributor 2'1 and thence into the discharge chamber 34 in which the liquid is caught by the stripping disk 35 and conveyed by same through channels 36 out of the drum.

rIhe specifically heavier liquid fiows through channels 31 into the inlet chamber 38, thence to thi, distributing channels Se? and; miscugli., the pistes paclrage1 32 inte the spa e W niet4 nii* ripheryfoirtnedrunn From;theretic-specihall ly heavier liquid passes channels 4| and? flows inter an upper' discharge cna-sniper;A 42# int which tire'v liquidi. caught byA stripping: elisir 4st and conveyed by. saine' throng-li; channelsA f4 outof the'- drurn The liquidi leviel wliere` the specihale l-y heavieir'liduidf is:y caugi tiie`1 stripping' dish 43? iiesf in ai distance :RT from the` aai-istat? rrr-i tation. The revolving? spe'e'd of the liquidon thisspot is iep;

The eonstructionsfornr of ti'iefc'entififugaif drum Egoiie's'pord .miili W thatiii-Fg onlyY tirol plates, as" showin lffi'g.y 3E arel bent several'i timesI s'ucnfV a manner:= tha' between adiacenti plates are snapedi channels formed. Tn'ebreaksf, 4t anni 4 8* are ari-ange between the distributing channels 4st andi 4e eil` the pia-te package. on. the operation of the. centrifugal machine theA currents orF the speeicaiiyf lighter and. speciricaily heavier liiuids. are crossingv each other in` the*i distiibutingcnamrielsil 45 anni 4151, SWElllasdr!thbetls 4511 m1655458' O'TEEpiate'Si so that the liquids are repeatedlymixed with caoli othern an'dthereafter separa-ted! again from eeen other. Byl means ori the repeated mixing off the liquids the?I extractioni resu-lt is improvedl and s'inc'e'-` iif connection with: an extraction stages: a;Y sharp' sepasadena the intermediate stage's isil less: importantQ- than;` tlierepeatedfrefe mixing, the cnitput:l off tire-f centnfrugaii machine is increased.

Iiii` the forni or the I centrifugail drumas: illustiered in F! 4, the:` platel paciiagef comprises tliif'e Sets?,I airfrm'er' se a'Ii iiiteirne'diaie" set? 'is' and.A outer? set. 4e? nf. distributing-z cnam nels between" these plate sets. The-t plates'v oi*- the;y intermediate set T13 are several times bent in sucitalma'nne'n that' between adjacent plates arc shaped channels are formed and that the uppcr and lie lower sides of tiieplatesare" alternatively turned" towards? the; axis of rotation of the drum. In the inner plate set 1i and` inthe outer plate set 49 a sharp? separation. off the liquids takes place, While in the intermediate plate set '[2'onl'y a comparatively, rough-.vsepara-l tion of the mixed liquids is performed and a re-mixing of the separated liquids takes place at the breaks 50 and 5l.

The specifically lighter liquid flows through the inlet pipe 52 into the inlet chamber 54 enclosed by the distributing tube 53, and through lower channels 55 to the vertical distributing channels S. The specifically heavier liquid flows through a pipe concentrical to the inlet pipe 52 and through openings 5l into the inlet chamber 58 and thence into the distributing channels 59. Between the inner and outer distributing channels 59 and 56 respectively, and the intermediate plate set 'i2 are mounted perforated cylinders 69 and 10 by which the mixing of both liquids is improved. After having passed the openings in these cylinders 69 and l0 the liquids ow in countercurrent through the intermediate plate package. Thereafter the specifically heavier liquid hows through the outer plate set 49 and into the chamber 6D at the periphery of the drum, from there through channels ll to the upper discharge chamber 62 from which the liquid escapes out of the drum by means of the stripping disk 63.

The specifically lighter liquid flows from the intermediate plate set l2 through the inner plate set 1| to the channels 64 and into the lower through,

stripping disl' 673i musttliayeesucl a': largeA diam; eter that the centrifugalcpressure of the specifically heavier liquidfoxnV itsv lefvel in the discharge chamber BTupto the distribution chani betweenl tite-outer andltiie; intermediate plate packageii is. smallert than: the'v centrifugal pirssuree of the?- spefoically lighter liquidi from itstlefv'cl iii-theimt-cliamcn 54'up to kth'e: aforementioned? diftifitution channels- 5thy The? Eig 5^ showsV am enlarged? portionl out out of the left side of the bent#intermediate-.plate package; -asslowrn irr Figa .45.v 'Ir-nenspace between trie@pialtes` is' contracte'd` atflthe 4break-'sf 501l` and 5'! i arrowsemarkcd indica-te@the directions. of the5v currentstV 'I' e1 ourren'tf of? the' specifically heavier' liquid indicated`-loy'sm'all circles and the?. cur-rentL of? the s specifically lighter: liquid? by smalti ero'sses` 'niet speciiiically heavierr liquid flows along that side of the 4plates."whiclr` is lfacing the? aai-isti ofrottiori, to tlief outside; and the speeicallylighte liquidinowsalongthatfside or thewr plates nich isturned from'- the-axisbff rotation; toetlie insides Thee-lower part ofthe plate Gliand?tlietupperfpartof'the platetil; as shown in Fig. 5,v are alternatel'y'fV turned towards and awayl from; the? axis: of? rotation; At the:y breaks andi ST5 thelquid currents?. are crossing each otlierf; aridiI by@ meansiiof the-contraction onl these spots'i aespe'fcally intensiverni-xingfofi"thek liquidstalies place:

What We claim is:

ill lrcountereur-rent extraction centrifuge-cempiising al. centrifugaldrum having' a multiple number of spacediepartf-paraller discs; positioned therein at an acute'zangle'to. the axis of rotation of the centrifii'ge'f;Y and: dividing the interior of said drum into multiple liquid flow channels, said discs being2 positioned! to's leave" the centralV and oute'rr portion" theiinterlior of said drum' substantially disc`-fifee, vsai discs-having an inner andi ar'i outer series of openings collectively' de; lining?? av iif'st andi af second-i liquid? passage: theree saidirst'liquidi passagepo'sitionedfrom tnemoptmtheibcttowofthezinterior'of saiddrum near! tli'e' centralportiorrthereot; sai-'dlsecond liq-A uid passage positioned from theibottom4 t'o-:the top of the interior of said drum near the outer portion thereof, first conduct means positioned for passing a specifically heavier liquid into said drum downward through said first liquid passage and over the surfaces of said discs, second conduct means positioned for passing a specically lighter liquid upward through said second liquid passage and over the opposite surfaces of said discs, whereby the two liquids are contacted at said rst and second liquid passages and in said flow channels between said first and second liquid passages, first discharge means positioned for discharging specifically heavier liquid from said disc-free outer portion of the interior of said drum and second discharge means positioned for discharging specifically lighter liquid from said disc-free central portion of the interior of said drum` 2. Extraction centrifuge according to claim 1 in which said rst and said second discharge means have liquid engaging portions for the discharge of the liquid so positioned from the axis of rotation of said drum that the centrifugal pressure of the specifically heavier liquid from said second liquid passages is smaller than the centrifugal pressure of the specifically lighter liquid from said first liquid passage.

7 3. Extraction centrifuge according to claim 2 in which said second liquid passage is positioned according to the following relation:

in which R equals the distance of said second liquid passage from the axis of rotation of the centrifuge; RH equals the distance of said rst liquid passage from the axis of rotation of the centrifuge; yH equals the specific gravity of the heavier liquid; and 7L equals the specic gravity of the lighter liquid.

4. Extraction centrifuge according to claim l in which said second conduct means is a stationvary feeding pipe and an inlet chamber, said inlet Ichamber being centrally located in said drum, 'said feeding pipe being positioned for passing specifically lighter liquid into said inlet chamber and being sealed with a packing against the wall of said inlet chamber.

5. Extraction centrifuge according to claim 4 in which the liquid engaging portions of said rst and said second discharge means are positioned at such a distance from the axis of rotation of said drum that the centrifugal pressure of the specically heavier liquid from said second liquid passage is smaller than the sum of the centrifugal pressure of the specifically lighter liquid from the axis of rotation of the drum to said second liquid passage plus the pressure with which the specifically lighter liquid is fed to said drum.

6. Extraction centrifuge according to claim 5 in which said second liquid passage is positioned according to the following relation:

in which R, is equal to the distance of said second liquid passage from the axis of rotation of the centrifuge; RH equals the distance of said first liquid passage to the axis of rotation of the centrifuge; fyH equals the specific gravity of the heavier liquid; fyL equals the specific gravity of the lighter liquid; and p equals the over pressure at which the specifically lighter liquid is fed into the drum.

7. Extraction centrifuge according to claim l in which said first discharge means and said second discharge means are each stripping disc means.

8. Extraction centrifuge according to claim 7 in which said rst discharge means is a stripping disc in communication with the outer disc-free portion of the interior of said drum and said second discharge means is a stripping disc in communication with the central disc-free portion of the interior of said drum.

9. Extraction centrifuge according to claim 1 in which said rst discharge means and said second discharge means each consist of members with an overfiow edge over which the liquid to be discharged is thrown out of the drum.

l0. Extraction centrifuge according to claim 1 in which said discs are bent at least once between said rst and said second liquid passage s0 that a portion of both their upper and lower surfaces faces the axis of rotation of the drum.

11. Extraction centrifuge according to claim 10 in which there are restricting means provided on the discs at the bend for restricting the flow channels therebetween.

12. Extraction centrifuge according to claim 1 in which said multiple discs consist of at least one inner, one intermediate, and one outer set of discs, said rst liquid passage being dened between said inner and said intermediate said discs, said second liquid passage being defined between said intermediate and said outer set of discs.

13. Extraction centrifuge according to claim 12 in which said intermediate set of discs are bent at least once so that a portion of both their upper and lower surfaces both face the axis of rotation of the drum.

PETER STEINACKER. AUGUST BYNG.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 2,036,924 Coutor Apr. '7, 1936 2,176,982 Thayer Oct. 24, 1939 2,291,849 Tomlinson Aug. 4, 1942 

